The Asteroid/Comet Connection's
daily news journal about
asteroids, comets, and meteors

Today's issue status: done, updated

• News briefs – comet news, meteor news, Rosetta news & crater news
  panel 2 – big NEO
• Risk monitoring – 2004 TF10 has been removed

Cover: Small object 2004 TE10 confirmation imagery from early 9 October 2004 UT by Gianluca Masi, Franco Mallia, and Roger Wilcox using the remote-controlled 14" f/7 Southern TIE (SoTIE) telescope at Las Campanas, Chile. North is up and east is left. For more about this object, which came within less than three lunar distances of Earth and Moon last Thursday, see yesterday's report.

Comet news:  Another comet has come undone. MPEC 2004-T44 today reports that C/2003 S4 (LINEAR) was observed by Pla D'Arguines Observatory in Spain early Saturday and on 24 and 25 September as two pieces. Animations have been posted to Pepe Manteca and Rafael Ferrando's Cometas site showing C/2003 S1-A and -B, and a possible third component.

Mike Nolan at Arecibo told the Minor Planet Mailing list (MPML) overnight that “We can attempt to observe Comet C/2004 S1 [Van Ness] at Arecibo, but it hasn't been observed much recently, and the position uncertainty may be enough to reduce our detection probability. Astrometry would be appreciated.” This comet was updated today in MPEC 2004-T49, and the circumstance of its discovery has now been made public in IAUC 8412 of September 28th.

Space.com has an article from October 8th which, in telling of preparations to send the Deep Impact spacecraft to Cape Canaveral (see October 3rd news), reports that “A select number of ground-based telescopes will observe the Deep Impact encounter in July 2005.”

Meteor news:  The University of Colorado at Boulder (CU-B) has a news release today telling how researchers will study the state's fifth meteorite fall (a witnessed event), reported by a family that “had just walked out their back door into the yard at 1:30 p.m. on Oct. 5, when the meteorite flew over their heads and landed about 100 feet [33 meters] ahead of them” in Berthoud, between Denver and Fort Collins. It is described as weighing “more than two pounds” (960gm) and “appears to be made of igneous rock,” which means it came from an object no smaller than the very largest Main Belt asteroids.

A fireball was also reported from the Denver area and Fort Collins much earlier that same day (see news).

Meteor news continued >>

Rosetta news:  A Rosetta mission update today reports the “Start of Last Lander Commissioning Block,” and notes that, beside successes, two problems were encountered.

Crater news:  A long and entertaining article at the Virginian-Pilot today tells about the work that went into last week's seismic testing around the Chesapeake Bay impact structure (see links in “Bits & pieces”). This wasn't just technical in nature but also required convincing people to let the U.S. Geological Survey “blow up things on their land” near what was “ground zero” at Cape Charles.

<< Meteor news continued from panel 1

Update:  Chris Peterson, who is on the science team, has posted a "Berthoud" Meteorite page with photos and details.

“ A meteorite like this probably produced a brilliant fireball [that] may have been visible from central and eastern Colorado, western Kansas and Nebraska, and southern Wyoming. ”

Anyone who saw this daylight fireball at around 1:15 to 1:30pm MDT on October 5th is asked to make a report.

The page shows how it appears that the meteor split at least once, late in its fall. Fiske Planetarium at CU-B, which posted photos on its home page today, is organizing a search party to look for more pieces on October 16th.

There is a news item today at KUSA-TV Denver. And for that link, thanks to Jeff Brower of the Global Meteor Scatter Network (see related links), who lives about 5 km. from where the meteorite fell.

Big NEO:  The biggest yet in a big year for big NEOs was announced today with MPEC 2004-T55 for 2004 TU12, discovered yesterday by the Siding Spring Survey in Australia. According to JPL, only 20 of some 3,020 NEOs have lower absolute magnitudes (brightness, H), indicating larger diameters. At a preliminary calculation of H=14.19, it is roughly estimated to be on the order of 4.9 km. (3 miles) wide. Gianluca Masi, whose team participated in the discovery confirmation, has posted an animation on his Near Earth Objects Corner page.

Risk monitoring 11 Oct.

The Monday Daily Orbit Update MPEC (DOU) has observation of 2004 TF10 from Farpoint Observatory in Kansas yesterday morning, and today NEODyS and JPL removed their impact solutions for this object, which JPL estimates to be on the order of 270 meters/yards wide.

The DOU reports observation of 2004 TL10 by LINEAR in New Mexico Saturday morning spanning 1.33 hours and yesterday morning over a period of 2.3 hours, and Farpoint also caught it yesterday morning. Today both risk monitors strongly lowered their risk assessments for this object and cut their impact solutions to just one each in 2041.

2004 TN1 was reported from Farpoint yesterday morning, adding about three minutes to the observation arc. Today NEODyS and JPL split in very slightly lowering or raising their risk assessments for this object, which JPL puts on the order of 170 meters wide.